Axillary Radiotherapy Reduces Lymphedema in Breast Cancer

Patients with early breast cancer had significantly less lymphedema if they received axillary radiotherapy instead of surgical lymph node dissection, according to the results of a study presented at the ESMO 2013 Congress of the European Society for Medical Oncology in Amsterdam.

For women with early breast cancer, determining whether the cancer has spread to the axillary (under the arm) lymph nodes is an important part of cancer staging. Evaluation of the axillary nodes often involves a sentinel lymph node biopsy. The sentinel nodes are the first lymph nodes to which cancer is likely to spread. If the sentinel nodes contain cancer, women often undergo more extensive lymph node surgery (axillary lymph node dissection). A common side effect of axillary lymph node surgery is lymphedema of the arm—swelling of the arm due to an accumulation of lymph fluid.

The AMAROS trial was a phase III clinical trial that included 4,806 patients—1,425 of whom were determined to have positive sentinel lymph nodes (those that contained cancer). These patients were randomized to receive surgical axillary dissection or radiotherapy.

The results indicated that the two treatment strategies produced similar low rates of axillary recurrence. The five-year disease-free and overall survival did not differ significantly between the two groups.

Women who underwent surgical axillary dissection had a 21 to 25 percent incidence of clinically significant lymphedema over five years, compared to 10 to 15 percent for those who underwent radiotherapy. Patients who underwent both surgery and radiation had the highest rates of lymphedema.

Lymphedema was assessed at 1, 3, and 5 years and compared among patients who underwent axillary lymph node dissection, axillary radiotherapy, or both forms of treatment. The assessment included clinical observation and measurement of arm circumference at multiple points.

Clinical observation revealed that lymphedema rates with surgery were 25.6 percent at 1 year, 21 percent at 3 years, and 20.8 percent at 5 years. In contrast, the rates of lymphedema with radiation were 15 percent at 1 year, 13.4 percent at 3 years, and 10.3 percent at 5 years.

Patients who underwent both surgery and radiation had lymphedema rates of 59.4 percent at 1 year, 44.8 percent at 3 years, and 58.3 percent at 5 years.

Lymphedema also was defined as an increase in arm circumference by more than 10 percent. By that definition, the rates at 1, 3, and 5 years were:

Surgery: 7.2 percent, 9.2 percent, and 11.7 percent

Radiation: 5.9 percent, 6.2 percent, and 5.7 percent

Both: 14.8 percent, 24.1 percent, and 29.2 percent

The researchers concluded that patients with early breast cancer had significantly less lymphedema if they received axillary radiotherapy instead of surgical lymph node dissection. They note: “Considering overall morbidity, axillary radiotherapy is the preferred treatment over axillary lymph node dissection in patients with a positive sentinel node. Since the combination of axillary surgery and radiation increases morbidity, this should, if possible, be avoided.”